Hypodermic syringe with magnetically actuated piston and needle



March 4, 1958 H. R. JOHNSON HYPODERMIC SYRINGE WITH MAGNETICALLY ACTUATED PISTON AND NEEDLE Filed Aug. 20, 1954 Q. mm m y. w x a E w v @w a A z. @M E mm o: ow Q9 00- m MN. mm mm m wg 5 a r .mm J 2. W mm w Q MK P K mm @m \5 5 ow itc r: in o I 11 k 3 a m A w 1 Q g g 9 m6 Qq mm 3 mm M. Q em 2 m9 United States Patent HYPODERMIC SYRINGE WITH MAGNETICALLY ACTUATED PISTON AND NEEDLE Howard R. Johnson, Collingswood, N. J., assignor to Howard Johnson Electrostatics & Electronics, Inc., Pound, Va., a corporation of Virginia Application August 20, 1954, Serial No. 451,173

11 Claims. (Cl. 128-173) This invention relates to hypodermic syringes and has for its principal object the provision of such an instrument in which the needle is solid and is Withdrawn before the medicine or other fluid is injected.

An important feature of the present invention is to provide a small, light weight hypodermic syringe electrically operated preferably, though not necessarily, by a foot switch.

A further object of the invention is to provide a hypodermic syringe in which the capsule is readily removable either after each operation or when the same capsule is used for a number of injections, a tip can be used for a single injection and then disposed of.

The invention contemplates a generally cylindrical body having therein at least one and preferably two solenoids for operating the plunger of the syringe in one or both directions and for operating a penetrating needle in one or both directions, the preference being that closing a single switch will advance the needle, instantly withdrawing it, and while withdrawing the needle advance the plunger in the cylinder of the capsule to discharge the fluid, at the same time operating a sterilizing device inside of the body which may be kept energized after the plunger has been returned to initial position.

In the drawings:

Figure 1 is a top plan view;

Figure 2 is a central vertical section;

Figure 3 is an enlarged sectional view of the disposable tip.

The casing is composed of a rear section and forward section 11 joined as at 12 by threading or any other connection. Centrally within the casing is a bobbin 15 providing what might be called a double spool having a central flange 16, a forward flange 17 and a rear flange 18. The larger and rearward portion of the spool houses a solenoid 20 which is the coil for the plunger while the smaller and forward portion of the spool houses a solenoid 21 which is the operating means for the hypodermic needle which differs from other syringes in that this needle is solid and is withdrawn into the housing prior to the administration of the fluid medicament. The armature 30 for the coil 20 is positioned axially in the casing and is held in inoperative position by a tension spring 31 fast to the armature 30 as by the clamp 32 and secured to a retainer 33, held at the rear of the syringe by a screw 34.

At the front of the armature 30 there is an elongated plunger piston 37 having the usual head or seal 38 fitting snugly in the cylinder 40 of the capsule. The axial movement of the core or armature 30 is limited by a stop member 43 which at the close of its return journey strikes an abutment 44 on the casing 10. The front limit of travel is formed by a button 46 sliding in a slot 47 and being held by a leaf-spring 48 in any one of the grooves 49. In previous models I have provided that the button 46 can be positioned with extreme accuracy anywhere in its travel but find that the four places are ample for all but very exceptional work.

2,825,332 l atented Mar. 4, 1958 The capsule is preferably of glass having a large head 50 integral with a tubular extension 51, the interior of which forms the cylinder or piston chamber 40, the end of the tube fitting snugly into a relatively heavy ring 55 which is slotted at its bottom as at 56 to provide a passage for the elongated arm 57 which carries the needle 60. The capsule frequently would be for one or a few uses and in such case would generally be closed except for the axial passageway 62 and the communicating passageway 61 but where, as illustrated, the chamber 40 receives fluid from a large reservoir I provide an intake nipple 64 having a spring-pressed valve 65 and being threaded as at 66 to receive a fairly large jar or a tube leading from such reservoir. I may also provide a springpressed valve 69 in the passageway 62, the spring of the valve being housed in a small cup 71 in the cap shell 72 which closes the discharge end of the syringe and preferably has a bayonet slot joint 73 with the front portion 11 of the syringe.

The disposable tip 70 is illustrated in detail in Fig. 3 and consists of a quite small cylinder preferably of plastic being about /2" long and /s of an inch in diameter. The two ends 75 and 76 are each tapered from the proximate face at about 2 to a groove 77 or 78, the former having bores 79 at right angles to each other and communicating with the axial bore 80 of the disposable tip. The rear face 82 of the tip is closed by a membrane 83 which may be held by a metal clip 84 but preferably is merely affixed to the tip by adhesive. The membrane is of any suitable quick-seal material so that when the extremely thin needle penetrates the membrane and is withdrawn liquid may not follow the needle being stopped by the membrane. It is my preference to provide an annular groove 86 in the front face 87 of the tip in order to secure a somewhat more firm contact with the tissue to be penerated.

The core or armature 90 which carries the needle 60 is preferably in the form of a hollow thimble, the base 93 of which in normal position rests against a central stop 94 integral with the spool or bobbin 15. The arm 57 is integral with the thimble. A sterilizing element 96, preferably in the form of a coil of resistance wire, is mounted on the casing 11 below the tubular wall 51 of the cylinder 40. A stop member 97 is adjustable in slots 98 and 99 in an electrical conduit cover 100 and in the bottom of the housing 11, respectively. The stop 97 has a. hole 103 therethrough to support and guide the fine needle 60. A nut 104 secures the stop which engages the head 107 of the arm 57. It has been found convenient to provide transparent windows 108 and 109 on each side of the forward portion 11 of the casing to observe the mechanism, the capsule itself being transparent and preferably of glass.

The electrical connections to the device are indicated diagrammatically, the cable 110 carrying a number of wires 111, either four or six in number preferably, and leading to the main coil 20, the auxiliary coil 21, and to the sterilizer 96. These members are energized preferably by a foot control switch which may have three separate elements, one for each coil and one for the sterilizer, but in my preferred models has a single switch which first energizes the coil 21 thus driving the needle 60 through the tip 70 to an extent governed by the stop 97. This action through a relay energizes main coil 20 so that the plunger operates instantaneously upon withdrawal of the needle and this is followed in turn by closing the current to the sterilizer. The armature 30, which is the head of the plunger, is withdrawn either manually or by the tension spring 31. While the core or plunger head 30 in delivering a maximum charge of medicine would come substantially in contact with the annular wall 94, I prefer that this wall shall not act as a stop memhe; for the plum; prcfeninmhat lthenstop member" 43 shall always strike the button I 7 What'I'claimis: j a a g a a a 11 in .a ltypodcrmic sy ringe," iad'ca'si'ng, 2a solenezidathere in, fan :a-rina'tnre coaxial saidj solenoid, an :elongated needle carried abyi ithe armature; and adapted etoI-he: proijected beyond the" casing upon .energiz atinn of ,said.sole --noid,. and a :m agnetic deyice.iorl retnxningwathe armature Leasing 1051s initial .p osition with the; needle inside of :the when the solenoid'is' tie-energized V a 2'.i=The syringe ;o'f claim '1 'with meanszforlde-lenergizthe. solenoid as the point tufethe needle is iprojected lbeynnd athe caSingg'end means: for :adjnstablyilimitinggthe fmivtzaird ..penet1'=ating movementefithe needle. t

113;? The syringe 20f :claim iw ith aesterilizen within-rthe :casing ancbsnrrpnndin'githe POiHL'Ofizfl'iemeGdlc when-the needle :isain inoperativepositioh withinathe. casing. f 7 *4. Thei syringeflof claim in zwhichithe sterilizer -:com- 7 prises ;a coil 50f resistance:wireiguidingihe .nedlexbetween -the. means dimiting.v movement .jiand the "forward. end of .itherca'sing. S Q a a V 5."In combination a'casing a capsule having a springpress'eddischarge valve:in;theacasing,.:aplungerlcooperating with the; capsule .to discharge Ellqllld fromi-th'e capsule, and means including a magnet :andit's armature-;for. ;mov-

-ingithel plnnger forwardtinlthetcapsule. V- a V 1'6, A-hypodermic syringe including :alcasing'havinga V -capsule' -.fo'rming' a cylinder having :a discharge orifice, ia

a piston plunger ope'rating in:the: cylinder to'dischargelfluid 7 kthrnsaidlorifice,1a penetrating needle housed. withinrthe 'casingfand movable parallel tto :the axis. of the cylinder,

a ho'll wi disposable tip carriedbyuthe' casingiin ,therpath I V of movement. of :tlieineedle, neansaforymovingthe piston plnngerandtheneedle independentlysofzeach:otherwhere V by -the needle may form a. temporarypassagewayontside Jof thec'asingfonthe fluid in the cylinderand the plunger,

7 may drive the finid into snChpassageway, and means within the :casing .for sterilizing .the needle aftercach ruse, said sterilizing means being positioned .coaxially of the dispo'sablettip andin proximity thereto.

'7. :In an "ejecting :device,';-a casing, atw oi aitially spaced 7 i-electro-magnets within the.- casing, a :firstiarmatnre axially movable invthe casing, a second armature coaxiaLthereto, a eylinder, aplunger "Within Lthe cylinder and r operably "connected :to the first armatnrega.needlemovable with t he=second armature'and adapted to be projected beyond Kile-discharge end of the casing, a-disposable holldw tip in-the casing axially aligned-with the travel ofthe needle, 7

"'a valved pa ssagcwayin the'fcasing connecting-the dis- 'charg'e end 7 ofthe cylinder with the hollow pf thedisposabel'tip',=-and'means fe'r successively energizin'g'the -mag nets, saids'e condarmatnre being positionedto movein one direction ;nnder urgef ene magnet and to be rea tnjnitiaL energized; V p

a 8. A hypodermic syringe V drical casing; a cap'for the discharge'en'd 'ofthe casing pnsitienn wl a I is V 5 having 7 therein ,a" discharge p as'sag'e, a 'portion' of which is coaxial with the casing, a sp ring-pressed valve in said need :t tofug he d schar e trical" means for. ejecting t.

turning the needle to initialposition. 7

r l ymdet nicr x having an intake valve and a discharge valve said casing having a'p'assage therein connecting'the'cylinderwithf the QQ -t J i disposables-nip, Ia; plungersip'r;oxin at e'igneviofasaidj e1 25 tioned electr c-magnets within .the casing, an -,arrnatnrc -wh,erc y;,0n. magne in P j h ee xqndjtheca ig;

sealini branl e xc in UHIEEDSTMESQ E -.-OTHER::REEERENCES 7 f a 5 io'fiiais comprising a generallycylinf a t 7 y,'-;as e2sab1.tipa; nisa s zsap' communicating with the dischai'geipassag'eway, a needle 7 movable' in a 'pathpassin'g'thrnsaid disposable'tipgelece'nd of gthe dev'ice,1= o' ste hzingn-the:needleianclziorre- Q v. Lee i e iya l dti ali r ing, a disposable tip therein; aplnrality'fofrelectro-mag anetic devices spacedjaxially in. .saidl.cylinder,a capsule 21 in a 1h tppdetmi synnge, in mi e #axialb eiiqs l ymdsnn s i ytin .n al; bsady havin an 

